'The old bridge is coming down," said Saunders. "A new structure has been completed and all the traffic is now on that structure."

I-15 traffic will be routed around the demolition via the on- and off-ramps, and Saunders says intermittent one-way traffic on 1100 South will be directed onto the new portion of the bridge to access the ramps. But he says it’s best for time-sensitive travelers to avoid the area altogether and use U.S. 89 to rejoin I-15 at points north and south of Brigham City.

Traffic from the Cache Valley area can continue southbound on U.S. 89 at its intersection with Main Street (state Road 13) in Brigham City, and rejoin I-15 via SR-315 in Willard at the 750 North Interchange (Exit 357), or at the South Willard Interchange via SR-126 (Exit 351).

Saunders says UDOT is coordinating the bridge demolition to disrupt traffic as little as possible.

A diverging diamond interchange is seen in this file photo courtesy Utah Department of Transportation.

Credit UDOT

"We just ask people to be patient during this," he added. "It's part of this process that has to be done, and we're going to take care of it as quickly as we can and then we'll be able to finish up this project by the end of the year."

The freeway will reopen Friday at 6 a.m. Saunders says the new diverging diamond interchange is expected to be complete by the end of the year. The new complex will be one of only five in the state.

UDOT says DDIs cost less to build and reduce the number of traffic signals needed to direct traffic from the usual three or four to two.